1 / 27

Energy Efficient Dynamic Provisioning in Data Centers : The Benefit of Seeing the Future

Energy Efficient Dynamic Provisioning in Data Centers : The Benefit of Seeing the Future. Minghua Chen http://www.ie.cuhk.edu.hk/~mchen. Department of Information Engineering The Chinese University of Hong Kong. TexPoint fonts used in EMF.

Download Presentation

Energy Efficient Dynamic Provisioning in Data Centers : The Benefit of Seeing the Future

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Energy Efficient Dynamic Provisioning in Data Centers: The Benefit of Seeing the Future Minghua Chen http://www.ie.cuhk.edu.hk/~mchen Department of Information Engineering The Chinese University of Hong Kong TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAAAAAA

  2. Skyrocketing Data Center Energy Usage • In 2010, it is ~240 Billion kWh, 1.3% of world electricity use. • It can power 5+ Hong Kong, or roughly the entire Spain. • The total bill is ~16 billion USD (~ GDP of New Zealand). Expected ~ 20% increase in 2012 (Datacenterdynamics 2011) [Jonathan Koomey2011]

  3. Energy Is Wasted to Power Idle Servers • Workload varies dramatically. • Static provisioning leads to low server utilizations. • Google server utilization: 30%. • US-wide server utilization: 10-20% (source: NY Times). • Low-utilized servers waste energy. • Low-utilized server consumes >60% of the peak power.

  4. Dynamic Provisioning: Save Idling Energy • Dynamically turn servers on/off to meet the demand. • Save up to 71% energy cost in our case study. Work Capacity Static Provisioning Dynamic Provisioning Dynamic Load Arrival Time

  5. Dynamic Provisioning: Challenges • Server on/off is not free: 0.5-6 hrsrunning cost. • Future workload isunknown. Dense workload Time Dynamic Provisioning Sparse workload Dynamic Load Arrival Time

  6. Existing Work • System building and feasibility examination (e.g., [Krioukov et al. 2010 GreenNetworking]) • Confirm that big saving is possible. • Algorithm design • Using optimal control approaches. (e.g., [Chen et al. 2005 SIGMETRICS]) • Using queuing theory approaches. (e.g., [Grandhi et a. 2010 PERFORMANCE]) • Forecast based provisioning (e.g., [Chen et al. 2008 NSDI]) Relying on knowing future workload to certain extent.

  7. Fundamental Questions • Can we achieve close-to-optimalperformance, withoutknowingfuture workload information? • Can we characterize the benefit of knowing future workload information?

  8. Our Contributions

  9. Problem Formulation total server running cost total server on-off cost • Objective: minimize server operational cost in [0,T]. • Linear cost model. • Elephant workload model (solutions also apply to mice model). • Zero server start-up time. • Challenges: Need to solve the integer problem in an online fashion. supply-demand constraint infinity integer variables

  10. A Tom & Jerry Episode The Road to MPhil

  11. Tom’s Puzzle: Idling-Cab Problem • When should Tom turn off the engine? • Too late: incur idling cost. • Too early: incur switching cost upon Jerry’s arrivals. • Turning on/off engine once costs the same as keeping it idle for minutes. • We call thebreak-even interval. University MTR Station

  12. Offline: Knowing the Entire Future • Elementary-school Tom is told that Jerry will arrive exactly after minutes. He compute an offline strategy: • If , then keep the engine idle. • If , then turn off the engine. • The benchmark offline cost: time • : the break-even interval.

  13. Online: Knowing No Future • Jerry’s arrival time is a mystery. • High-school Tom keeps the engine idle for minutes before turning it off. • Online cost <= 2 * offline cost (2-competitive) • Can we do better than 2? online cost = 2*offline cost online cost = offline cost time • : the break-even interval • .

  14. Benefit of Randomization • Undergrad Tom timeshares among different turn-off times to improve the ratio to e/(e-1)1.58. • Can we do even better? S1 loses. S2 partially wins. S1 wins.S2 loses. Both S1 and S2 win. time • : the break-even interval. Strategy S2 Strategy S1

  15. The Benefit of Seeing the Future • (Seeing partial future) Post-graduate Tom sees whether Jerry will arrive in the next minutes (). time • : the break-even interval. look-ahead window

  16. The Benefit of Seeing the Future • Tom’s strategy: Keep the engine idle for minutes, and turn it off if no arrival in sight. • Online cost <= * offline cost • Timeshare to improve the ratio to . • Are these numbers the best possible? online cost = (2-) * offline cost online cost = offline cost time • : the break-even interval.

  17. The Idling-Cab Problem: Summary • Tom proves that his strategies are the best possible. • But in practice, there are more than one cab.

  18. Tom’s Topic: Idling-Cabs Problem (Tough) • How to minimize the aggregate waiting cost? • New key issue: who should serve the next Jerry? University MTR Station

  19. Who Should Serve the Next Jerry? fair but energy-wasting.. • Hong Kong’s first-in-first-outrule: • Tom’s last-in-first-out rule: • De-fragment the waiting periods to minimize the on/off times! energy-efficient. time Tom #2 Tom #1 Tom #1 has waited longer than Tom #2. waiting periods serving periods

  20. Tom’s Solution for Idling-Cabs Problem • Job-dispatching module: last-in-first-out. • Easy to implement with a stack. • Individual cabs: solve their own idling-cab problems. Departing customer Arriving customer Idling cab ID Customer departure Customer arrival Off cab ID

  21. Tom’s MPhil Thesis: the Idling-Cabs Prob. • Observation: Future information beyond will not further improve performance.

  22. Greening Data Centers Animal-Intelligent (AI) • Servers Cabs Jobs Customers …

  23. Numerical Results • Real-world traces from MSR Cambridge. • The break-even interval is 6 unit time (1hr).

  24. Cost Reduction over Static Provisioning • Save 66-71% energy over static provisioning. • Achieve the optimal when we look one hour ahead.

  25. CSR/RCSR are Robust to Prediction Error • Zero-mean Gaussian prediction error is added. • Standard deviation grows from 0 to 50% of the workload

  26. Summary • Theory-inspired solutions for dynamic provisioning in data centers. • Achieve the best competitive ratios and . • Save 66-71% energy over current practice in case studies. • Solutions have been extended beyond the basic setting. • Look-ahead errors. (Tan’s thesis) • Server set-up delay. (Tan’s thesis) • Cooling and power conditioning cost. (ACM e-Energy 13) • We are exploring with industry partner to transfer the technology.

  27. Thank you! • Minghua Chen (minghua@ie.cuhk.edu.hk) • http://www.ie.cuhk.edu.hk/~mhchen

More Related